I'm sure Gartner's math was accurate, but most of us don't really have a handle on how big a zettabyte really is.

In previous computing eras we only had to really have a feel for the real disk-space size of a couple of major measurements at a time. In the paleosilithic era, nomadic proto-geeks used kilobytes and megabytes to measure the size of their hard drives (and "floppy drives," though this might have been the result of anxiety or heavy drinking, both of which are known to cause otherwise firm drives to droop).

In more recent eras we used gigabytes and terabytes, with the occasional petabyte thrown in to make it seem as if we were ahead of our time.

That will force those of us who insist on staying current enough on new technology to be able to identify it in taste tests to learn a whole series of other terms, all of which reflect an order-of-magnitude leap in size over the previous one, several of which might be in use at any one time.

The problem is that those of us who grew up with mega-, giga- and terabytes have a good feel for how much space they describe, how much stuff we could put on a drive (hard, soft or thumb) with that much space, and how many of one metric fits into another.

The same is not true of zettabytes, yottabytes or vundabytes.

Next generation data metrics: More odd names, even huger piles of data

Fortunately the web has come to the rescue in the form of ConvertUnits.com, a slightly academic-feeling site that will convert any size of data-measurement unit to another instantly and for free.

The pull-down boxes on the main site only list measurement units up through petabyte, but the ConvertUnits home page is a kind of catchall that lets you plug in any two of the metric, date, salary, molecular weight and storage-space measurement units the site supports and it will do the conversion for you.

How to convert odd and unusual units of measure

There are other conversion sites, too, of course. OnlineUnitConversion happily calculates that one centimeter equals 10,000,000,000,000,002,048 zeptometers, which is fine if you can remember to replace "meters" with "bytes" when you paste the results.

ConvertUnits.com also does odder measures, including this page that converts an ell (a medieval version of the Old Testament-era cubit) to zeptometer (one 1,000,000,000,000,000,000,000 th of a meter (1 * 10 -21), though the odds that you'll need it are slim unless you're building an Ark with very, very, very tight manufacturing tolerances.